Improvement in binding-screws



UNITED STATES PATENT EEIGE.

FRANK snunz, or PALOMA, ILLINOIS.

IMPROVEMENT IN BINDING-SCREWS.

Specification forming part of Letters Patent No. 137,801, dated Api il 15, 1873; appli ation filed December 11, 1872.

To all whom it may concern Be it known that I, FRANK SHURZ, of Paloma'7 in the county of Adams and State of Illinois, have invented certain new and useful Improvements in Thumb-Screws, of which the following is a full, clear, and exact description, which will enable others skilled in the art to which my `invention appertains to make and.

and necessary41 to operatethem; to this end' my invention consists in the employment of ratchet-teeth engaged by a catch in such a manner that the screw when set will be firmly held in position until the catch is released.

In the drawing, A represents a thumb-screw ot the class usually employed for the purpose of binding wires to electrical instruments. a a are ratchet-teeth cut in the periphery of the screwhead. B is a spring-catch, attached to the post which receives the screw, and this spring engages the teeth a a. The inclination of the face of the teeth a a is such that when the screw is turned down the engagement of the spring B with the teeth will prevent the latter from being accidentally turned in the opposite direction. An outward pressure upon the spring B will carry it from its engage ment with the teeth, and the thumb-screw may then be unscrewed.

Having thus described my invention, what I claim as new7 and desire to secure by Letters Patent, is-

Clhe thumb-screw A provided with ratchetteeth and a sprin g-pawl, substantially as shown and described.

FRANK SHURZ.

Witnesses MIKE DUNN, D. W. HAGGERTY. 

